Our pond is has muck around the edges and we use it for party and swimming...
It's a little hard to know how to answer without knowing the nature of your "muck." If you're referring to filamentous algae, yes, spot treating with algaecides is possible. If the "muck" is an accumulation of silt and organic matter, that becomes more costly to manage, but still possible. To start, have a look at this fact sheet and let me know if it addresses your needs: